In order to transport pallets, containers and materials throughout a factory, wheeled tugger carts are often used. These tugger carts allow an individual to deliver the pallets, containers and materials to the desired workstation in the factory. It can be appreciated that after the containers are transported to the desired locales in the factory, these containers must be unloaded or removed from the support platform of the tugger cart. However, given the significant weight of a loaded container, it may difficult for a worker to remove the container from or to unload the container positioned on the support platform of the tugger cart. Hence, it is highly desirable to provide a tugger cart that allows for a worker to simply and easily remove a loaded container from or unload the container positioned on the support platform of the tugger cart.
It can be further appreciated that unloading the pallets, containers or materials positioned on the elevated support platforms of corresponding tugger carts is often difficult and time consuming. For example, a container may have to be reorientated on the support platform in order to allow for access to the interior thereof by a worker. When the pallets, containers or materials transported on a tugger cart are of significant size and/or weight, it may be difficult for a user to reorientate the pallet, container or material delivered to the workstation. Consequently, it is highly desirable to provide a tugger cart which allows for a user to easily orientate the pallets, containers, or materials transported thereon to allow access to the interior thereof by a worker.
Therefore, it is a primary object and feature of the present invention to provide a tugger cart for transporting pallets, containers and materials throughout a factory that is simple to use and inexpensive to manufacture.
It is a still further object and feature of the present invention to provide a tugger cart for transporting pallets, containers and materials throughout a factory that allows for a user to reorientate the pallets, containers and materials supported thereon to facilitate access to the interior thereof by a worker.
It is a still further object and feature of the present invention to provide a tugger cart for transporting pallets, containers, and materials throughout a factory that is simple to use and inexpensive to manufacture.
In accordance with the present invention, a tugger cart is provided for transporting a load having a weight. The tugger cart a support frame and a bed pivotably mounted to the support frame for receiving the load thereon. The bed is movable between a first position wherein the bed is lies in a generally horizontal plane and a second position wherein the bed is a predetermined acute angle to the horizontal plane. A wheel assembly is operatively connected to the support frame for supporting the support frame above a supporting surface.
The tugger cart also includes a bed locking structure for locking the bed in the first position. The bed locking structure has a retractable pin operatively connected to one of the bed and the support frame that movable between along a pin axis between an extended position and a retracted position. A sleeve is connected to the other of the bed and the support frame. The sleeve defines a recess for receiving the pin in the extended position. An actuator is operatively connected to the pin for moving the pin between the extended and retracted positions.
It is intended that the bed of the tugger cart pivot from the first position to the second position at a predetermined rate independent of the weight of the load. The tugger cart includes a cylinder assembly operatively connecting the bed to the support frame for controlling the predetermined rate. The cylinder assembly includes a cylindrical housing having first and second ends and an inner surface defining a cavity in the housing for receiving a fluid therein. The cylinder housing is operatively connected to one of the bed and the support frame. A piston slidably extends through the cavity in the housing. The piston has a first end connected to the other of the bed and the support frame and a second end. A flange projects from the piston and is positioned within the cavity so as to divide the cavity in the housing into first and second portions. The flange terminates at a radially outer edge that forms a slidable interface with the inner surface of the housing. A differential pressure valve has an upstream input communicating with the first portion of the cavity and a downstream output communicating with the second portion of the cavity. The flow rate of the fluid at the output of the differential pressure valve is constant in response to various pressures of the fluid at the input. The cylinder assembly may also include a check valve for controlling the flow of fluid from the second portion to the first portion of the cavity.
In accordance with a further aspect of the present invention, a tugger cart is provided from transporting a load. The tugger cart includes a support frame and a bed pivotably mounted to the support frame for receiving the load thereon. The bed is movable at a predetermined rate from a generally horizontal position to a tilted position wherein the bed is at a predetermined angle to horizontal. A differential pressure valve controls the predetermined rate.
The tugger cart also includes a wheel assembly operatively connected to the support frame for supporting the support frame above a supporting surface and a handle assembly extending from the support frame. A locking structure is operatively connected to the bed for locking the bed in the horizontal position. The locking structure includes a retractable pin operatively connected to the bed. The pin is movable between along a pin axis between an extended position wherein the pin is receivable in an opening in the support frame and a retracted position. An actuator is operatively connected to the pin for moving the pin between the extended and retracted positions.
The tugger cart may also include a cylinder assembly having a cylindrical housing with first and second ends and an inner surface defining a cavity in the housing for receiving a fluid therein. The cylinder housing is operatively connected one of the bed and the support frame. A piston slidably extends through the cavity in the housing. The piston has a first end connected to the other of the bed and the support frame and a second end. A flange projects from the piston and is positioned within the cavity so as to divide the cavity in the housing into first and second portions. The flange terminates at a radially outer edge that forms a slidable interface with the inner surface of the housing.
The differential pressure valve has an upstream input communicating with the first portion of the cavity and a downstream output communicating with the second portion of the cavity. The flow rate of the fluid at the output of the differential pressure valve is constant in response to various pressures of the fluid at the input. A check valve controls the flow of fluid from the second portion to the first portion of the cavity.
In accordance with a still further aspect of the present invention, a tugger cart is provided for transporting a load. The tugger cart includes a support frame and a bed pivotably mounted to the support frame for receiving the load thereon. The bed is movable between a generally horizontal position and a tilted position wherein the bed is at a predetermined angle to horizontal. Control structure is provided for controlling the rate at which the bed pivots from the horizontal position and the tilted position.
A locking structure operatively is connected to the bed for locking the bed in the horizontal position and a connection assembly operatively is connected to the support frame for interconnecting the tugger cart to a second tugger cart. The control structure includes a cylindrical housing having first and second ends and an inner surface defining a cavity in the housing for receiving a fluid therein. The cylinder housing is operatively connected one of the bed and the support frame. A piston slidably extends through the cavity in the housing. The piston has a first end connected to the other of the bed and the support frame and a second end. A flange projects from the piston and is positioned within the cavity so as to divide the cavity in the housing into first and second portions. The flange terminates at a radially outer edge that forms a slidable interface with the inner surface of the housing.
The control structure includes a differential pressure valve having an input communicating with the first portion of the cavity and an output communicating with the second portion of the cavity. The flow rate of the fluid at the output of the differential pressure valve is constant in response to various pressures of the fluid at the input.